If you have a question during lecture, please ask! Someone else is probably wondering about the same point.

Chemistry
What does the subject chemistry bring to mind?
Matter

Composition/Structure

Properties

Chemistry
Matter (the stuff of chemistry)
• matter is physical material of universe • it is anything that has mass and occupies space We will focus on matter composed of elements from the periodic table

Chemistry
Matter (the stuff of chemistry)
• matter is physical material of universe • it is anything that has mass and occupies space We will focus on matter composed of elements from the periodic table

Composition/Structure
• • components of matter (e.g., atoms) and relative proportions how these components are connected in together

Chemical Properties & Change
What are chemical changes?
Chemical changes or ‘reactions’ transform one form of matter into different kinds with different compositions.
H2 H2/O2

H2O

Chemical Properties & Change
What does chemical change imply about chemical properties?
While reading a textbook of chemistry, I came upon the statement “nitric acid acts upon copper” and I determined to what this meant. In the interest of knowledge I was even willing to sacrifice one of the few copper cents then in my possession. I put one of them on the table, opened a bottle labeled “nitric acid”, poured some of the liquid on the copper, and prepared to make an observation. But what was this wonderful thing I beheld? The cent was already changed, and it was no small change either. A greenish-blue liquid foamed and fumed over the cent and over the table. The air became dark red. How could I stop this?......... Ira Remsen, 1901

Compare Gold and Sodium? Au + H2O Na + H2O Different substances react in different ways– have different chemical properties

Classification of Matter
Atoms, molecules and such?
Elements– different types of atoms Molecules & Macromolecules– contain two or more atoms

Mixtures and such?
No substance No matter
Can sample be separated by physical process?

Yes mixture No

decomposed by chemical process?

Yes

Yes

element

uniform throughout?

compound homgeneous heterogeneous

States of Matter
Three common states of matter: Solid Liquid Gas

Density & Composition
What is difference between mass and density?
Density is the mass in a unit volume of a substance: density = mass/volume

extensive vs. intensive properties
Mass is an extensive property– it depends on “how much”. Density is an intensive property– it is independent of the amount observed.